I am using my usual combination of Kyma, Kyma-Connect, and Linnstrument. I am seeing the behaviour in my own patches, as well as in the provided Linnstrument demo patches. I can get sound if I set the Midi Mode on the Linnstrument to One Chan, but it seems to be automagically switched back to ChPerNote (as it should be of course) and then it stops working. I can see the note data flowing into Kyma in the Show Midi Messages window.
The fake keyboard works, and I can even use the Linnstrument as a keyboard by turning off the MPE setting in Kyma's Midi Configuration and setting the L to One Chan. Of course I don't get the correct MPE responses by doing so.
I have looked for any other settings that could be wrong, but they all seem right, as in I am using v2.2.1 of the L firmware, and the appropriate setting is selected in the Midi Configuration panel, etc.